GUPPI RAW output mode

[radonnachie]

It'd be helpful in a number of scenarios to be able to upchannelise the data and save that data as GUPPI RAW. Namely because a few tools ingest RAW but have no simple way to upchannelise in situ.

[savinshynu]

It would be definitely helpful if rawspec can upchannelise the raw data and save them in raw formats without integration. That would be helpful to conduct some diagnostic tests with the telescope data.

[siemion]

This actually came up in the past, and indeed it would be an extremely useful feature. It would also be good if this mode included the option to selectively write out subsets of a single coarse channel (e.g. upchannelize only a single coarse channel, and then only write out a subset of that channel, for the purposes of extracting complex voltages around a signal of interest). It would also be interesting, although not motivated by any particular current need, to inverse fft back to a (usually lossy) broadband channel.

[radonnachie]

I've just completed a GuppiRAW C library that has file-output capabilities. I'll look to implement this feature soon.

[radonnachie]

We'll probably want to optionally requantize to integer at the end. That introduces a large task, that I'll leave to a subsequent issue and PR. Initially all guppi outputs will be floating point.